1. Field of the Invention
The present invention relates to an idle air control apparatus supplying an idle air to an intake passage at a downstream side of a throttle valve via a bypass air passage, and more particularly to an idle air control apparatus in a multiple throttle body supplying a bypass air controlled by a single plunger valve to an intake passage at a downstream side of each of throttle valves of a plurality of adjacent throttle bodies via respective bypass air passages.
2. Description of the Conventional Art
In FIG. 3 of Japanese Unexamined Patent Publication No. 2004-211612, there is shown a first example of an idle air control apparatus provided with a plurality of intake passages, and supplying a bypass air controlled by a single plunger valve to an intake passage at a downstream side of each of the intake passages via a plurality of bypass air passages.
In this case, a description will be given by using names and reference symbols used in the publication.
An upstream side first idle air distribution path 10A extending along a longitudinal direction of a throttle valve shaft 3, and an upstream side second idle air distribution path 11A extending along the longitudinal direction of the throttle valve shaft 3 are open to a side wall 7B of a slidable valve guide tube 7 integrally formed with a throttle body 1, a downstream side first idle air distribution path 10B extending along a longitudinal direction of a first intake passage 2A is branched from the upstream side first idle air distribution path 10A, and the downstream side first idle air distribution path 10B is open to the first intake passage 2A at a downstream side of a throttle valve 4. Further, a downstream side second idle air distribution path 11B extending along a longitudinal direction of a second intake passage 2B is branched from the upstream side second idle air distribution path 11A, and the downstream side second idle air distribution path 11B is open to the second intake passage 2B at a downstream side of the throttle valve 4. In this case, an idle air introduction path 9 is open to a bottom portion 7A of the slidable valve guide tube 7.
Accordingly, a valve body 14 arranged within the slidable valve guide tube 7 controls the openings of the upstream side first idle air distribution path 10A and the upstream side second idle air distribution path 11A open to the slidable valve guide tube 7, whereby an idle air is controlled, and the idle air is supplied to the second intake passage 2B at the downstream side of the throttle valve 4 from the downstream side second idle air distribution path 11B as well as being supplied to the first intake passage 2A at the downstream side of the throttle valve 4 from the downstream side first idle air distribution path 10B.
Further, a second example of the idle air control apparatus is shown in FIG. 6 of the publication mentioned above.
In accordance with this example, a slidable valve guide tube 55B is provided within a control case 55 formed independently from the throttle body, an idle air introduction path 56 is open to a bottom portion 55C of the slidable valve guide tube 55B, and a first idle air distribution path 57 and a second idle air distribution path 58 are open to a side wall 55D of the slidable valve guide tube 55B.
Further, a downstream side of the first idle air distribution path 57 is coupled to a first intake passage 51B via a first distribution path 61, and a downstream side of the second idle air distribution path 58 is connected to the second intake passage 51A via a second distribution path 62.
Accordingly, a valve body 60 arranged within the slidable valve guide tube 55B controls the openings of the first idle air distribution path 57 and the second idle air distribution path 58 open to the slidable valve guide tube 55B, whereby the idle air is controlled, and the idle air is supplied to the first intake passage 51B via the first distribution path 61, and is supplied to the second intake passage 51A via the second distribution path 62.